v0.3.2

Breaking changes:

• args, multifunction and multimethod are now reserved
  keywords in NBIND_CLASS sections (put them and the nbind.h
  include after your own code to avoid conflicts).
• Improve upper case property name handling, getPROP
  now becomes PROP instead of pROP.

Other changes:

• Allow renaming bound classes.
• Support const and non-const pointers and references.
• Support overloaded functions (requires renaming each overload).